In a facility (plant) having a large and complicated structure such as a nuclear power plant, a non-contact type three-dimensional measuring device such as a 3D laser scanner or a 3D reconfiguration technique using an image acquires data on a laser radiation surface (as build data) from an existing building structure and thereby measures a range of a wall surface of the existing building structure, and a plan of reconstructing and additionally installing an instrument and a plan of loading an instrument are performed.
Such a three-dimensional measuring device can simultaneously acquire lots of data by radiating laser to the surroundings while rotating the 3D laser scanner installed at a base point when measuring an object to be measured.
However, it is difficult to measure a three-dimensional surface shape of the entire object to be measured by measuring at one time because a shadowed portion is made.
Therefore, measurement is performed several times with the base point changed by changing the position of the 3D laser scanner, and obtained measured data measured from a plurality of positions are overlapped to decrease as much as possible the shadowed portion, thereby obtaining data in a three-dimensional surface shape (three-dimensional data).
Conventionally, there is a three-dimensional CAD technique of creating engineering data of the facility existing in the large and complicated structure by forming a three-dimensional CAD model using the thus acquired three-dimensional data.
As an application example of the three-dimensional CAD technique, for example, a three-dimensional CAD model creating system is disclosed which can automatically acquire design specification data on various plant instruments and easily correct a design three-dimensional CAD model.
Incidentally, in the facility in the large and complicated structure, it is necessary to grasp not only the shape of a partitioned wall surface in the facility but also the place of a physical body or an instrument existing therein, a vacant space, the workability in the surroundings, and the accessibility of a remote-operated robot, especially under an environment which a person hardly enters. In this case, it is important to efficiently and early specify the existence of space.
The above-described conventional technique of creating the three-dimensional CAD model can specify the position of the space to some extent.
However, accurate data cannot be created unless engineering information of all facilities in a search object range is combined. Therefore, the operation of combining the engineering information will take huge amount of time.
Besides, for a region which has not been scanned, its shape is presumed by manual operation, resulting in variations in quality of completed three-dimensional data depending on the experience and skill of an operator.
In addition, the details of the operation of creating the three-dimensional data is not remained as an operation result, so that when an actual state differs from the model, review becomes required for the operation of correcting the presumed shape and a reconstructing and additional construction plan and an instrument loading plan associated therewith.
As described above, in the conventional three-dimensional CAD model creating system, it is difficult to accurately express the space measured by the three-dimensional measuring device in a short time.